Hard cast alloy



rates The present invention relates to metal alloys and more particularly to metal alloys useful for hard surfacing, and as hard metal castings.

It is an object of the present invention to provide a composition or alloy that will form a hard, corrosionresistant surface.

Another object of the invention is to provide an alloy that may be cast to form a hard, corrosion-resistant body.

A further object of the invention is to provide a hard facing alloy that will form a hard, long-wearing surface.

Still another object is to provide a relatively inexpensive hard facing alloy.

More particularly, it is an object of the invention to provide an alloy which has a relatively low coefiicient of friction so that a minimum of heat is generated between two contacting bodies formed of or surfaced with such alloy when such "bodies are moved relative to one another.

Other objects and advantages of the invention will become more apparent hereinafter.

Alloys made in accordance with the invention fall within the following ranges:

Sulfur and phosphorus may be present in nominal amounts without harm to the alloy and small amounts of copper may also be tolerated.

Tungsten may be utilized in place of vanadium and molybdenum for part or all of these latter elements. As a replacement for one of the elements tungsten may be present within substantially the same range as the replaced element but preferably in somewhat lesser amount. As a replacement for both vanadium and molybdenum it preferably is present in amounts of from about 3.0% to 8.0%. Tungsten is, at the present time at least, more costly than vanadium and molybdenum, but its presence ice will render the alloy somewhat harder and give it greater thermal stability and may be desired for certain purposes in spite of the greater cost of the alloy.

A particular advantage of the alloy is that it has a relatively low coefficient of friction with respect to itself and is therefore highly useful in making metal-to-metal seals for rotating shafts and the like since by reason of the low coeflicient of friction less heat is developed at the face-to-face seal than is developed with other hard facing alloys. The alloy has high thermal stability and retains its hardness even after being heated to relatively high temperatures. It also retains its wear resistance at quite high temperatures.

The alloys of the invention are also relatively hard and wear resistant, the alloys having a hardness of about Rockwell C as cast, and a hardness of about Rockwell C after heat treatment.

.It will be noted that the major portion of alloys of the invention comprises relatively inexpensive ingredients and the alloys are, therefore, relatively low in cost. As indicated earlier the alloys of the invention may be successfully cast and may also be used for hard facing metal parts in which case the alloy may be applied by conventional welding techniques.

Having illustrated a preferred embodiment of the invention, it should be understood that the invention permits of modification in arrangement and detail. We claim as our invention all such modifications as come within the true spirit and scope of the appended claims.

We claim:

1. An alloy containing 1.7 to 5.0% carbon, 1.0 to 5.7% manganese, 0.2 to 2.2% silicon, 1.0 to 6.3% nickel, 24.0 to 37.0% chromium, 2.0 to 6.0% molybdenum, 2.8 to 5.0% vanadium, and the balance iron.

2. An alloy containing 3.8 to 4.2% carbon, 3.8 to 4.2% manganese, 1.0 to 1.4% silicon, 1.8 to 2.2% nickel, 25.0 to 28.0% chromium, 3.4 to 3.8% molybdenum, 2.4 to 2.7% vanadium, and the balance iron.

3. An alloy containing 1.7 to 5.0% carbon, 1.0 to 5.7% manganese, 0.2 to 2.2% silicon, 1.0 to 6.3% nickel, 24.0 to 37.0% chromium, 4 to 11% of metals selected from the class consisting of molybdenum, vanadium and tungsten, and the balance iron.

4. An alloy containing 1.7 to 5.0% carbon, 1.0 to 5.7% manganese, 0.2 to 2.2% silicon, 1.0 to 6.3% nickel, 24.0 to 37.0% chromium, 3.0 to 8.0% tungsten, and the balance iron.

References Cited in the file of this patent FOREIGN PATENTS 457,841 Canada July 5, 1949 

1. AN ALLOY CONTAINING 1.7 TO 5.0% CARBON, 1.0 TO 5.7% MANGANESE, 0.2 TO 2.2% SILICON, 1.0 TO 6.3% NICKEL, 24.0 TO 37.0% CHROMIUM, 2.0 TO 6.0% MOLYBDENUM, 2.8 TO 5.0% VANADIUM, AND THE BALANCE IRON. 